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在我们自己研制的具有恒温加热进样系统的激光质谱仪上实验获得了气相萘分子的共振增强多光子电离/飞行时间质谱(REMPI-TOFMS),以及萘母体离子C10H8 和一些主要碎片离子C8H6 、C6H6 、C5H3 、C4H3 、C3H3 在264~280 nm的分质量光谱.结合在266 nm激发波长下实验得到的这些离子的光强指数及不同激光能量下的分支比,对母体离子及主要碎片离子的生成机理进行了探讨:在该波段范围内,萘母体分子首先吸收一个光子从基态跃迁至激发态,激发态分子再吸收一个光子而电离产生母体离子C10H8 ;碎片离子C8H6 、C6H6 、C5H3 、C4H3 、C3H3 则是由母体离子进一步吸收光子解离形成的,并给出了可能的解离通道. 相似文献
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在800nm飞秒激光作用下对碘乙烷多光子电离解离过程进行了研究,获得了碘乙烷分子的多光子电离飞行时间(MPI-TOF)质谱.光强指数分析表明母体离子主要发生3+3共振增强多光子电离(REMPI)过程.根据部分碎片离子占总离子信号的百分比对激光强度的依赖关系,讨论了碘乙烷的多光子电离解离机制,得出了C2H5I分子的多光子电离(MPI)属于母体离子离解阶梯模式.文中分析了母体离子在该波长下主要两条解离通道,其中C-I键的断裂为主要通道.应用高斯03在B3LYP/3-21G基组上计算了两条通道能量的变化,理论进一步验证了实验结果的合理性. 相似文献
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在我们自己研制的具有恒温加热进样系统的激光质谱仪上实验获得了气相萘分子的共振增强多光子电离/飞行时间质谱(REMPI-TOFMS),以及萘母体离子C10H+8和一些主要碎片离子C8H+6、C6H+6、C5H+3、C4H+3、C3H+3在264~280 nm的分质量光谱.结合在266 nm激发波长下实验得到的这些离子的光强指数及不同激光能量下的分支比,对母体离子及主要碎片离子的生成机理进行了探讨:在该波段范围内,萘母体分子首先吸收一个光子从基态跃迁至激发态,激发态分子再吸收一个光子而电离产生母体离子C10H+8;碎片离子C8H+6、C6H+6、C5H+3、C4H+3、C3H+3则是由母体离子进一步吸收光子解离形成的,并给出了可能的解离通道. 相似文献
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本文报道了在280-287.5 nm区域内,通过共振增强多光子电离-时间飞行质谱和质量选择光电离激发谱对四氯化碳分子的紫外多光子解离通道进行的研究,并对部分碎片离子的分质量激发谱进行了标识和归属.结果表明, CCl_4共振吸收两个光子到达4s里德堡态,然后快速解离成CCl、C、CCl_2、CCl_3等中性碎片,其中CCl是最主要的解离通道,其次是C碎片产生通道,而CCl_2、CCl_3等碎片产生通道几乎可以忽略. 相似文献
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在355 nm激光作用下,利用多光子电离技术结合飞行时间质谱(TOF-MS)对苯甲醚分子进行了研究。实验结果表明苯甲醚分子的多光子电离机制属于母体分子电离-解离模型。通过对主要碎片离子的可能形成过程的讨论,得出该波长下母体分子离子解离的主要有两种通道,但是随激光能量的增强,甲基移除通道逐步占据优势成为主要通道。应用高斯软件采用HF/6-31G(d) 方法对苯甲醚分子和苯甲醚阳离子基态的几何构型进行优化得到其稳定构型,并计算了苯甲醚分子离子及其初级解离产物的能量。比较两条通道的碎片离子能量的变化,理论验证了实验中苯甲醚分子主要解离通道的合理性。 相似文献
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在243-263nm紫外光波段通过质量选择光电离激发谱研究了丙酮(CH3COCH3)的光化学反应通道。分析母体离子CH3COCH3^+和碎片离子CH3CO^+、CH3^+的光电离激发谱和质谱峰宽可以知道:此光波段丙酮分子的光化学反应主要包括了丙酮分子经由(S1,T1)中间态产生母体离子的(1+1)双光子电离通道,母体离子进一步解离产生碎片离子CH3^+的“光电离-光解离”通道和丙酮分子经由(S1,T1)中间态解离成中性自由基碎片CH3CO后再进一步被双光子电离的“光解离-光电离”通道。由母体离子光电离激发谱双光子阈值波长(255.67nm)给出的丙酮电离势(IP)为(9.696±0.004)eV。 相似文献
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利用飞行时间质谱仪在超声射流冷却条件下探讨了532 nm激光作用下CH3I分子的多光子电离(MPI)解离过程和机制,得到了分子的飞行时间质谱,质谱中包含较强的I 、CH3 离子信号和较弱的CH3I 、CHn (n≤2)、C 、H 离子信号.不同激光能量下的质谱信号在排布上相似,但在强度上有差别.在532 nm激光作用下CH3I分子的多光子电离包括两个过程:一是CH3I分子由双光子激发到A带解离,生成I原子和CH3基团,然后再吸收光子实现中性碎片电离;另一通道是CH3I分子由三光子共振激发到里德堡C态,处于激发态的母体分子继续吸收两个光子电离形成母体离子,碎片离子可由母体离子解离形成. 相似文献
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Summary We report the measurements of the3
D(3s4d)-3
P(3s3p)3
D(3s5d)-3
P(3s3p), and3
P(3p
2)-3
P(3s3p) transition frequency of MgI, the fine-structure separation and isotope shift between24Mg and26Mg. The measurements have been performed in a metastable atomic beam; a good agreement is found for data already existing
in the literature. The accuracy of the measurements reported in this paper is mainly limited by the Doppler broadening of
theI
2 transitions used as a reference and by the precision in the knowledge of the related wavelengths. 相似文献
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The systematic application of band contour techniques to account for most of the observed features of the ir spectra of s-triazine and s-triazine-d3 have been made as well as a critique as to the limitations of such methods. The experimental and computer methods used to study the gas phase infrared band contours of s-triazine and s-triazine-d3 are out-lined. Contours of the five E′ fundamentals of s-triazine have been recorded under moderate resolution and analyzed to give the Coriolis constants , i = 6–10. The effects of l-resonance are very apparent for ν8 and ν9, in the form of holes in the Q branches of these bands. Under the highest resolution available, ν6 and ν10 also show l-resonance effects. Values of the l-doubling constants were obtained for these four fundamentals. One of the parallel A2″ fundamentals of C3H3N3 (ν12) has also been studied. It lies close to ν10(E′) and an A × E type of second-order Coriolis resonance may be the cause of the intensity enhancement observed in the inner wings of the ν12 and ν10 bands. Hot bands of the type (νi + nν14 ? nν14) have been observed in the contours of ν8, ν10, and ν12. This is felt to be responsible for the large difference between our observed zeta sum (?1.30) and the theoretical sum (?1.00).The gas phase infrared band contours of the five E′ and 2A2″ fundamentals of C3N3D3 have also been recorded under moderate resolution. From P-R separations and by computer simulation of the contours, values of the Coriolis constants have been obtained for the E′ modes. The effects of l-resonance have been observed for ν8(E′) and ν10(E′) and values of the l-doubling constants have been estimated. An extensive series of hot bands of the type (ν12 + nν14 ? nν14) has been observed in the contour of the ν12 (A2″) fundamental. The mass effect on the Coriolis constants has been discussed.Infrared band contours of the overtone 2ν7 and seven degenerate E′ combination bands of C3N3H3 have been recorded under moderate resolution. Analysis of these contours using the P-R separation method and computer simulation of the contours has given values of for these bands. Fermi resonance between 2ν7 and ν6 has been analyzed. The importance of considering both the observed contour as well as the observed frequency when assigning higher tone bands is illustrated. 相似文献
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The infrared spectra of ammonia-borane, BH3NH3, and two of its deuterated isotropic species, BD3ND3 and BH3ND3, isolated in argon matrix at liquid hydrogen temperature have been measured. Well resolved bands for these three isotopic species have been observed for all the fundamentals. A complete frequency assignment based on C3v molecular symmetry has been made. A set of force constants have been calculated from the data for the two isotopes BH3NH3 and BD3ND3 using a valence force field. The agreement between experiment and frequencies calculated from these force constants for the mixed isotopic species, BH3ND3, substantiates the present assignment. 相似文献
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P. A. Markovin V. V. Lemanov M. E. Guzhva P. P. Syrnikov T. A. Shaplygina 《Physics of the Solid State》2014,56(5):989-995
The temperature dependences of the dielectric constant and dielectric hysteresis loops in ceramic samples of (1 ? x)SrTiO3?x KNbO3 and (1 ? x)SrTiO3?x KTaO3 (0 ≤ x ≤ 0.3) solid solutions prepared using different heat treatments have been investigated. Phase diagrams of the studied solid solutions have been constructed in the T-x coordinates. It has been shown that, after quenching of samples (spontaneous cooling at room temperature after long-term heating at the sintering temperature of the ceramic samples), the temperature of the induced phase transition increases because of the weakening of random electric fields associated with nonisovalent impurities due to their “frozen” nonequilibrium redistribution. For small concentrations x, strong dielectric relaxation is observed in the temperature range of 150–250 K. A model of relaxing centers, which is based on the local charge compensation of heterovalent impurities, has been proposed. 相似文献
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O_3 fast and simple treatment-enhanced p-doped in Spiro-MeOTAD for CH_3NH_3I vapor-assisted processed CH_3NH_3PbI_3 perovskite solar cells 下载免费PDF全文
We demonstrate a simple and fast post-deposition treatment with high process compatibility on the hole transport material(HTM) Spiro-MeOTAD in vapor-assisted solution processed methylammonium lead triiodide(CH_3NH_3PbI_3)-based solar cells. The prepared Co-doped p-type Spiro-MeOTAD films are treated by O_3 at room temperature for 5 min,10 min, and 20 min, respectively, prior to the deposition of the metal electrodes. Compared with the traditional oxidation of Spiro-MeOTAD films overnight in dry air, our fast O_3 treatment of HTM at room temperature only needs just 10 min,and a relative 40.3% increment in the power conversion efficiency is observed with respect to the result of without-treated perovskite solar cells. This improvement of efficiency is mainly attributed to the obvious increase of the fill factor and short-circuit current density, despite a slight decrease in the open-circuit voltage. Ultraviolet photoelectron spectroscopy(UPS) and Hall effect measurement method are employed in our study to determine the changes of properties after O_3 treatment in HTM. It is found that after the HTM is exposed to O_3, its p-type doping level is enhanced. The enhancement of conductivity and Hall mobility of the film, resulting from the improvement in p-doping level of HTM, leads to better performances of perovskite solar cells. Best power conversion efficiencies(PCEs) of 13.05% and 16.39% are achieved with most properly optimized HTM via CH_3NH_3I vapor-assisted method and traditional single-step method respectively. 相似文献
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Abstract Spectra of polycrystalline samples of NH3BF3 and ND3BF3 at 300 K and 98 K have been recorded in the frequency range 20-400 cm?1. Isotopic frequency ratios are used to interpret the observed features in terms of the known molecular and crystal structures. 相似文献
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JETP Letters - Films of CH3NH3PbI3 organometallic perovskite, which is currently considered as a promising basic material for new-generation solar cells, as well as films containing CsPbI3... 相似文献